Oil slinger



Aug. 11, 1964 P. J. EBERT 3,144,097

OIL SLINGER Filed Aug. 50, 1962 s Sheets-Sheet 1 Aug. 11, 1964 Filed Aug. 30, 1962 P. J. EBERT OIL SLINGER 3 Sheets-Sheet 2 P. J. EBERT OIL SLINGER Aug. 11, 1964 3 Sheets-Sheet 5 Filed Aug. 30 1962 United States Patent 3,144,097 OIL SLINGER Paul J. Ebert, Milwaukee, Wis., assignor to Briggs & Stratton Corporation, Milwaukee, Wis., a corporation of Delaware Filed Aug. 30, 1962, Ser. No. 220,397 4 Claims. (Cl. 18413) This invention relates to splash type lubricating devices for internal combustion engines, particularly single cylinder gasoline engines in which the crankshaft is disposed on a vertical axis, and the invention refers more specifically to improvements in splash type lubricating devices of the type disclosed and claimed in the patent to H. S. Brown, No. 2,669,322, dated February 15, 1954.

In single cylinder gasoline engines having a vertical crankshaft, such as are now commonly used on rotary power lawn mowers, for example, the bottom of the crankcase is located well below the bottom of the horizontally disposed cylinder, to insure that the oil level in the crankcase will normally be below the mouth of the cylinder at all times, so that oil will not be able to seep through the piston rings and foul the engine. This, however, places the oil in the crankcase well beyond the reach of the moving parts within the crankcase, and introduces the problem of feeding oil to such moving parts, and particularly to the cylinder wall and the upper crankshaft bearing. The splash type lubricating device of the aforesaid patent to H. S. Brown affords a means for effecting the necessary distribution of lubricating oil to the cylinder wall and the moving parts within the crankcase, comprising a rotatable slinger partly immersed in the oil in the crankcase, gear connected with the crankshaft to be rotated thereby, and having radially projecting paddles or vanes on its periphery. Such a slinger is simple, dependable and substan tially less expensive than a pump.

While entirely satisfactory is operation on the small displacement engines on which it has heretofore been widely used, the oil slinger of the Brown patent has been found to offer a possibility of trouble on single cylinder engines of somewhat larger displacement (on the order of 14 cubic inches), in which the upper crankshaft bearing is spaced somewhat farther from the slinger, and wherein the oil supply in the crankcase can have its surfaces at more widely spaced apart maximum and minimum operating levels. When tried in such larger displacement engines it was found that the slinger disclosed in the Brown patent did not consistently direct oil to the upper crankshaft bearing, especially at low engine speeds and when the oil level in the crankcase was somewhat low but within normal operating limits.

With the foregoing in mind, it is the general object of the present invention to provide a rotary splash type lubricating device for both large and small internal combustion engines having vertical crankshafts, which device can be relied upon to effect consistent lubrication of the upper main bearing at all speeds of the engine, even when the oil supply in the engine crankcase is at a relatively low level.

More specifically, it is an object of the present invention to provide and improved rotary oil slinger or splash type lubricator of the general type disclosed and claimed in the aforesaid Brown patent, having a plurality of specialized paddles thereon, each operative at a different level of oil in the crankcase to direct lubricant to the upper crankshaft bearing thus insuring consistent lubrication of said upper hearing all through a relatively Wide but normal range of levels of oil in the crankcase, and at all operating speeds of the engine.

Thus it is a specific object of this invention to provide a rotary crankshaft driven oil slinger or splash lubricator of the character described having a separate scoop-like projection or paddle on its periphery for each of a plurality of different oil levels in the crankcase, each paddle being adapted to throw oil directly toward the upper crankshaft hearing when oil in the crankcase is at the level for which that paddle is provided, to thus insure consistent lubrication of said upper bearing under all normal conditions of engine operation.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

FIGURE 1 illustrates a single cylinder engine incorporating a rotary lubricating device of this invention, the view being mainly in elevation but with portions of the crankcase of the engine cut away to show the lubricator;

FIGURE 2 is a more or less diagrammatic front view of the lubricator or oil slinger of this invention shown in relation to the upper crankshaft bearing of an engine in which it is installed and illustrating how the slinger directs oil to said bearing when oil in the crankcase of the engine is at a high level;

FIGURE 3 is a view similar to FIGURE 2 but showing how the oil slinger throws oil to the upper crankshaft bearing when oil in the engine crankcase is at a low level;

FIGURE 4 is a fragmentary sectional view of the oil slinger, on an enlarged scale, taken on the plane of the line 4-4 in FIGURE 1; and

FIGURE 5 is a perspective view of the oil slinger per se.

Referring now to the accompanying drawings, the numeral 5 designates generally an internal combustion engine of the single-cylinder type having a crankcase 7, and a crankshaft 8 mounted on a vertical axis.

Inside the crankcase, as is conventional, are a number of moving parts which are in need of lubrication at all times during operation of the engine, including a lower crankshaft main bearing 9, an upper crankshaft bearing 19 and a connecting rod bearing 11, as well as the cylinder wall and the Wrist pin bearings (not shown). The supply of lubricating oil for the engine is held in a sump 12 comprising the lower portion of the crankcase and which is defined in part by a lower end wall or cover 13 that also supports the lower main bearing 9.

Oil from the sump is thrown onto the moving engine parts inside the crankcase by means of a rotary oil slinger 14 of this invention, which is of the general type disclosed and claimed in the aforesaid Patent No. 2,669,322. In general, the slinger comprises a unitary disc-like member 16, preferably molded of a plastic material such as nylon, mounted for free rotation on a stub shaft 17 that has its axis substantially offset from the vertical and somewhat inclined to the horizontal. The slinger is gear connected with the crankshaft to be rotatably driven thereby and is partly immersed in the oil in the crankcase so that portions on its periphery successively enter and emerge from the oil as they move in their orbits during slinger rotation.

The geared connection between the slinger and the crankshaft is provided by circumferential bevel gear teeth 19 formed on the rear face of the slinger member 16, around the periphery thereof. In this case the gear teeth on the slinger meshingly engage With the timing gear 26 on the camshaft 21, but they could of course be engaged with the gear 22 on the crankshaft by which the camshaft gear is driven, or with an idler gear (not shown) driven from the crankshaft.

The stub shaft upon which the slinger rotates is carried by a bracket 24 which is fixed in the crankcase of the engine. Details concerning the mounting of the bracket and stub shaft can be found in Patent No. 3,028,848 to R. K. Catterson, issued April 10, 1962.

In the embodiment of the invention herein illustrated, the. front face of the disc-like member 16 has four forwardly projecting bosses 25 formed thereon, which serve to mount the fiyweiglits 26 of a centrifugally responsive governor mechanism of the type disclosed in the copending application of R. K. Catterson, Serial No. 211,079, filed July 19, 1962.

On the slinger of the present invention there are two specialized projections or paddles 27 and 28, each intended to throw oil directly to the upper main bearing it when oil in the crankcase is at a different level. Thus the paddle 27 serves to lubricate the upper main bearing when oil in the crankcase is at a normally high level, while the paddle 28 directs oil to said bearing when the oil level in the crankcase is fairly low.

The two paddles 27 and 28 are located substantially at diametrically opposite sides of the periphery of the disclike slinger member, and of course move in a common orbit. Each paddle comprises, in effect, an extension of one of the bosses 25 that carry the flyweights of the centrifugally responsive governor, and each merges into its boss in a concave fillet 29 of substantial radius. Outwardly of the fillet each paddle is generally triangular in cross section, as viewed from the side of the slinger (see FIGURE 5), and has a leading face 30 that faces generally in the circumferential direction of slinger rotation.

It is of the essence of the present invention that the leading faces of the two paddles are. differently disposed with respect to radial planes through the slinger axis that intersect corresponding portions of the two paddles, and therefore when oil in the engine crankcase is at any one level the two paddles emerge from the oil, in the course of their orbital rotation in different attitudes. Specifically, the paddle 27 has its leading face so disposed as to face generally upwardly when that paddle is near the top of the portion of its orbit in which it moves upwardly, while the leading face of the paddle 28 is so disposed that it faces generally upwardly shortly after the paddle 28 begins to move upwardly in its orbital motion.

Preferably the slinger is so located in the crankcase that when the oil therein is near its full level, the surface of the oil is above the center of the slinger, and when the oil is at its lowest permissible level its surface is below the center of the slinger. Hence the leading face of the paddle 27 extends along generally horizontal lines just as said paddle emerges above the surface of oil near the full level, while the paddle 27 has its leading surface extending along horizontal lines just as that paddle is in an orbital position at which it is emerging above the surface of oil at or near the lowest permissible level. It will therefore be apparent that the paddle 27 is effective to lubricate the upper main hearing when oil in the crankcase is at or near its highest normal level, while the paddle 25; provides for lubrication of said bearing when oil in the crankcase is at or near its lowest permissible level.

Preferably the leading face of each paddle is concavely curved in the general direction of slinger rotation, as best seen in FIGURE 5, and this curvature, together with the concave fillet 29, causes the leading face of each paddle to have a scoop-like concavity which enhances its ability to lift and throw oil. As can also be seen from FIGURE 5, the leading face of each paddle may also be inclined forwardly in the direction of slinger rotation with respect to the plane of the slinger, so that the paddle has a tendency to throw oil obliquely upwardly, in a direction to provide a forward component to the trajectory of the discharged oil. This forward inclination of the leading face of the paddle has been found desirable for affording satis factory direction of oil to the upper main bearing, even though said bearing is actually located somewhat to the rear of the plane of the disc-like body of the oil slinger. Apparently the rotating crank throw 35 creates a strong circular current of air in the crankcase which imparts a rearward deflection to oil thrown upwardly by the paddles; and the forward inclination of the leading faces of the paddles compensates for the effect of this air current to the extent necessary to cause oil thrown upward by the paddles to hit the lubricant hole for the upper main bearing.

Because of the above mentioned substantially triangular cross sectional shape of the paddles, it will be observed that each of them tends to move through the oil in the crankcase in a somewhat streamlined attitude, at least in the portion of its orbit in which it has a downward component of motion, thus causing less resistance to rotation of the slinger than would a flat paddle. The fact that there are only two paddles on the slinger of this invention, rather than the six employed on the specific lubricator of the Brown patent, further minimizes the torque required to drive the present slinger.

Although it takes very little power from the engine, the lubricator of this invention nevertheless provides sufficient generalized splashing of oil around the interior of the crankcase to insure that all of the moving parts therein will be adequately lubricated. When the oil level is such that paddle 27 directs lubricant to the upper main bearing, paddle 28 throws oil in other directions, and when the oil level is such that paddle 28 affords lubrication for the upper bearing, paddle 27 splashes oil in other directions. In addition, the bosses 25 that carry the governor flyweights, and the teeth 19 formed on the rear face of the slinger, also throw a certain amount of oil around the interior of the crankcase, as do elongated forwardly extending projections 36 on the slinger member which serve as stops for the flyweights and which are more particularly described in the aforesaid conpending application of R. K. Catterson.

Obviously, the slinger could be provided with more than two paddles, having their leading faces disposed in different attitudes, but in practice it has been found that the two paddle oil slinger herein illustrated affords very adequate librication under all normal conditions of operation.

From the foregoing description, taken together with the accompanying drawings, it will be apparent that this invention provides a rotary oil slinger for an engine having a vertical crankshaft journaled in spaced upper and lower bearings, whereby a constant stream of lubricating oil is directed to the upper bearing at all operating speeds of the engine, and at all normal operating levels of oil in the engine crankcase.

What is claimed as my invention is:

1. An oil slinger of the rotary type which is adapted to be partly immersed in a supply of oil in the lower portion of the crankcase of an internal combustion engine and to be rotatably driven in one direction about a fixed axis that is so offset from the vertical that as the slinger rotates a point on its periphery has alternate upward and downward components of orbital motion by which such point is alternately carried above and below the surface of the o l, said oil slinger being characterized by: a pair of circumferentially spaced apart paddles so disposed on the sl nger as to move orbitally therewith in consequence of slinger rotation, each of said paddles having a leading face, the leading faces of the two paddles being different ly disposed with respect to planes radial to the slinger axis that intersect corresponding portions of said faces of the two paddles so that the leading faces of the two paddles emerge in different attitudes from oil in a crankcase at a given level, but so that the leading face of one of said paddles has substantially the same attitude when it emerges from oil at a high level that the leading face of the other paddle has when it emerges from oil at a lower level, whereby each paddle is eifective at a different level of oil in the crankcase to throw oil toward a part fixed in the upper portion of the crankcase.

2. The oil slinger of claim 1, further characterized by the fact that said leading surface on each paddle is concave.

3. In an internal combustion engine having a crankcase in which a supply of oil may be held with its surface at varying levels, an oil slinger of the rotary type mounted in the lower portion of the crankcase and rotatably driven in one direction about a fixed axis which is so offset from the vertical that as the slinger rotates a point on its periphery has alternate upward and downward components of orbital motion by which such point is alternately carried above and below the surface of oil in the crankcase, said slinger being characterized by: a first paddle on the slinger, spaced from the slinger axis and having a leading face which is so disposed with respect to a plane radial to the slinger axis and intersecting a portion of the first paddle that said leading face has a predetermined upwardly facing attitude at a point in the orbit of the first paddle near the top of its upward component of orbital motion, so that said first paddle is effective to throw oil to a part at a fixed location in the upper part of the crankcase when the supply of oil in the crankcase is at a high level; and a second paddle on the slinger, circumferentially spaced from the first paddle and having a leading face which is differently disposed with respect to a plane radial to the slinger axis and which intersects a corresponding portion of the second paddle, so that the leading face of the second paddle has substantially the same upwardly facing attitude at a point in the orbit of the second paddle near the bottom of its upward component of orbital motion, so that the second paddle is effective to throw oil to said part when the supply of oil in the crankcase is at a low level.

4. In an internal combustion engine having a crankcase in which a supply of oil may be held with its surface at varying levels, an oil slinger of the rotary type mounted in the lower portion of the crankcase and rotatably driven in one direction about a fixed axis which is so offset from the vertical that as the slinger rotates a point on its periphery has alternate upward and downward components of orbital motion by which such point is alternately carried above and below the surface of oil in the crankcase, said slinger being characterized by: a pair of circumferentially spaced apart paddles on the periphery of the slinger, so located as to move substantially in a common orbit as the slinger rotates but having leading surfaces which are differently disposed with respect to radial planes through the slinger axis that cut corresponding portions of the paddles, one of said paddles having its leading surface so disposed as to have a predetermined upwardly facing attitude at its orbital point of emergence from oil in the crankcase when such oil is at a level above the center of the slinger, and the other of said paddles having its leading surface so disposed that it has a corresponding upwardly facing attitude at its orbital point of emergence from oil in the crankcase when such oil is at a level below the center of the slinger, so that a part at a fixed location in the upper portion of the crankcase receives consistent lubrication from oil thrown thereto by the slinger regardless of variations in the quantity of oil in the crankcase between maximum and minimum permissible levels.

References Cited in the file of this patent UNITED STATES PATENTS 1,562,642 Holmstrom Nov. 24, 1925 

3. IN AN INTERNAL COMBUSTION ENGINE HAVING A CRANKCASE IN WHICH A SUPPLY OF OIL MAY BE HELD WITH ITS SURFACE AT VARYING LEVESL, AN OIL SLINGER OF THE ROTARY TYPE MOUNTED IN THE LOWER PORTION OF THE CRANKCASE AND ROTATABLY DRIVEN IN ONE DIRECTION ABOUT A FIXED AXIS WHICH IS SO OFFSET FROM THE VERTICAL THAT AS THE SLINGER ROTATES A POINT ON ITS PERIPHERY HAS ALTERNATE UPWARD AND DOWNWARD COMPONENTS OF ORBITAL MOTION BY WHICH SUCH POINT IS ALTERNATELY CARRIED ABOVE AND BELOW THE SURFACE OF OIL IN THE CRANKCASE, SAID SLINGER BEING CHARACTERIZED BY: A FIRST PADDLE ON THE SLINGER, SPACED FROM THE SLINGER AXIS AND HAVING A LEADING FACE WHICH IS SO DISPOSED WITH RESPECT TO A PLANE RADIAL TO THE SLINGER AXIS AND INTERSECTING A PORTION OF THE FIRST PADDLE THAT SAID LEADING FACE HAS A PREDETERMINED UPWARDLY FACING ATTITUDE AT A POINT IN THE ORBIT OF THE FIRST PADDLE NEAR THE TOP OF ITS UPWARD COMPONENT OF ORBITAL MOTION, SO THAT SAID FIRST PADDLE IS EFFECTIVE TO THROW OIL TO A PART AT A FIXED LOCATION IN THE UPPER PART OF THE CRANKCASE WHEN THE SUPPLY OF OIL IN THE CRANKCASE IS AT A HIGH LEVEL; AND A SECOND PADDLE ON THE SLINGER, CIRCUMFERENTIALLY SPACED FROM THE FIRST PADDLE AND HAVING A LEADING FACE WHICH IS DIFFERENTLY DISPOSED WITH RESPECT TO A PLANE RADIAL TO THE SLINGER AXIS AND WHICH INTERSECTS A CORRESPONDING PORTION OF THE SECOND PADDLE, SO THAT THE LEADING FACE OF THE SECOND PADDLE HAS SUBSTANTIALLY THE SAME UPWARDLY FACING ATTITUDE AT A POINT IN THE ORBIT OF THE SECOND PADDLE NEAR THE BOTTOM OF ITS UPWARD COMPONENT OF ORBITAL MOTION, SO THAT THE SECOND PADDLE IS EFFECTIVE TO THROW OIL TO SAID PART WHEN THE SUPPLY OF OIL IN THE CRANKCASE IS AT A LOW LEVEL. 